Mr Noor was charged in the July 2017 death of Ms Ruszczyk, a 40-year-old dual citizen of the U.S. and Australia.
Justine's fiancé Don Damond described the cruel reality of Justine calling police for help, only to be killed by an officer she should have been able to trust.
Ms Damond was shot dead when she approached a police vehicle in an alley behind her Minneapolis home in 2017.
A jury of 10 men and two women got the case Monday afternoon after three weeks of testimony.
Prosecutors called Noor's shooting of Damond, who was unarmed, "reckless" and the prime minister of Australia at the time, Malcolm Turnbull, said it was "inexplicable".
Noor testified that he believed there was an imminent threat after he saw a cyclist stop near the police cruiser, heard a loud bang and saw Harrity's "reaction to the person on the driver's side raising her right arm".
Tim Walz says he's asking for all "evidence and background" on the case from state investigators.
In his only public statement about the shooting, Noor testified that after he heard the loud noise, he saw fear in Harrity's eyes and heard his partner yell, "Oh Jesus!" as he went for his weapon.
Noor was immediately handcuffed and led from court.
Real Madrid: Zidane slams display in Rayo Vallecano defeat
The hosts got the victor with a penalty kick converted by Adrian Embarba in the 23rd minute after a foul awarded by video review. Future: "We have three games to go and we have to play differently". "I have to live through these hard moments like today".
Now that the trial's over, the family may continue with its lawsuit against Noor, his partner Harrity, former Minneapolis Police Chief Janee Harteau, current Chief Medaria Arradondo and the city of Minneapolis.
Noor was acquitted of the more serious second-degree intentional murder charge.
The 33-year-old ex cop and his partner had been responding to Damond's 911 call and driving down the alley behind her home.
The defendant said he "had to make a split-second decision" and shot Ms Damond through the auto window. Sentencing is scheduled for June 7. But Hennepin County prosecutors said Noor overreacted and failed to properly assess the situation before firing a gunshot into Ruszczyk's abdomen.
Under the law of Minnesota, third-degree murder is fatally hurting someone without the intent to kill and "without regard for human life".
"Justine was killed by a police officer, an agent of the state", he said.
Prosecutor Amy Sweasy countered that Noor violated Minneapolis police training policies - and endangered the life of his partner and an eyewitness, a teenage cyclist.
Testifying for the prosecution, Lt. Derrick Hacker of the Crystal Police Department in Minnesota said that Noor's use of deadly force was "excessive and objectively unreasonable".
Noor was sacked after he was charged. They were sequestered the whole time, staying in a Minneapolis hotel room rather than going home the night between days they deliberated.
A former policeman in the U.S. state of Minnesota has been found guilty of murdering an unarmed Australian woman.